which of the following is not a function of conducting zone of respiratory tract?

Options

A. conduction of air
B. clears the air of foreign particles
C. humidification of air
D. gaseous exchange

Answer

To solve the question "Which of the following is not a function of the conducting zone of the respiratory tract?", we can follow these steps:

### Step 1: Understand the Structure of the Respiratory Tract
The human respiratory tract is divided into two main zones:
- **Conducting Zone**: This includes all the structures that conduct air to the lungs but do not participate in gas exchange. It consists of the nostrils, nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.
- **Respiratory Zone**: This is where gas exchange occurs, primarily consisting of the alveoli.

**Hint**: Remember the distinction between conducting and respiratory zones.

### Step 2: Identify Functions of the Conducting Zone
The conducting zone has several key functions:
1. **Air Conduction**: It conducts air to the lungs.
2. **Air Filtration**: It filters out foreign particles and pathogens using mucus and cilia.
3. **Humidification**: It humidifies the air and warms it to body temperature before it reaches the lungs.

**Hint**: Focus on the roles that prepare the air for gas exchange.

### Step 3: Recognize the Function of the Respiratory Zone
The primary function of the respiratory zone is:
- **Gas Exchange**: This is where oxygen is absorbed into the blood and carbon dioxide is expelled.

**Hint**: Gas exchange is a critical function, but it occurs in the respiratory zone, not the conducting zone.

### Step 4: Analyze the Options Provided
Given the options, we need to identify which one does not belong to the functions of the conducting zone. The correct answer will be the one that refers to gas exchange.

**Hint**: Look for the option that mentions gas exchange or any related term.

### Step 5: Conclusion
After analyzing the functions and understanding the distinction between the zones, we conclude that the option that refers to gas exchange is not a function of the conducting zone.

**Final Answer**: The option that states "gaseous exchange" is not a function of the conducting zone of the respiratory tract.